Lubricant



Patented Oct. 31,;

John C. Zimmer and George M. MoNulty, Union, 1., assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application January 1, 1M2,

SeriaiNo. 425,332 I 3- Claims. (Cl. 252-48) This invention relates to lubricants and more particularly to extreme pressure lubricants.

It is known that the film strength or load carryingcapacity of plain mineral lubricating oils, which is ordinarily not sufllciently high for proper lubrication of moving metal parts which contact each other under high pressures, such as certain typees of bearings, engines, hypoid gears, etc;, can be greatly increased by adding thereto various chemical compounds or materials containing active halogen and/or sulfur and sometimes phosphorus. Such extreme. pressure agents, as formerly made with only relatively low amounts of chlorine and sulfur, were soluble in almost all types of mineral lubricating oil base stocks; but when an attempt is made to use ex treme pressure agents which contain large amounts of chlorine and sulfur, it is found that 5% of sulfur are satisfactorily soluble in mineral 3 lubricating oil base stocks having a viscosity index below about 50.

It has also been discovered that even highly paraflinic or other mineral lubricating 011 base stocks in which such ex'treme pressure-agents are normally insoluble may be used satisfactorily, or sulfurized with the extreme pressure agent, by

adding thereto'a substantial amount such as 5-50% or generally about -30% by volume. based on the volume of parafllnic oil, of a solvent extract obtained by treating a mineral, lubricating oil base stock with solvents having a selective solvent action for aromatic and unsaturated hydrocarbons, for instance, by extracting a lubricating oil stock by phenol, liquid sulfur dioxide,

r otnitrobenzene. Extreme pressure agents within the scope of this invention may be chlorinated derivatives of aliphatic or aromatic hydrocarbons such as partion is somewhat slow. More elevated temperachlorination in a much shortertime and there- 5 fore are more economical, and also enable the preparation of chlorinated derivatives containing up to about 60% of chlorine. The present inven-- tion is, therefore, particularly applicable to the use of extreme pressure agents comprising chlo- 10 rinated derivatives made by chlorination at temas sulfurized fatty oils or sulfurized mineral oils.

or various organic sulfur'compounds, such as sulfldes, mercaptans, etc. However, it ispreferable to use as the extreme pressure agent a single s material in which both chlorine and sulfur have been incorporated into the'same compounds and this may readily be accomplished by first chlorinating a suitable hydrocarbon material, such as the paraiiin and kerosene described above, and

' subsequently sulfurizing the resultant chlorinated hydrocarbon derivatives, as by treating them with sulfur or an inorganic sulfide, such as sodium sulfide or polysulfide or a mixture thereof with sulfur and sodium hydroxide, a mercaptideor a thiocarbonate or xanthate;

One example .of a suitable extreme pressure lubricating agent is made by chlorinating kerosene at a temperature of about 220 F. to a chicrine content of aboutf50'-55% and treating the resultant chlorinated kerosene with sulfur, caus tic soda, and'sodium hydrogen sulfideto make a sulf-urized chlorinated. kerosene derivative containing about 20-50% of chlorine and about -4-l0% oi ,sulfur.

A sample of an extreme pressure agent made as 40 just described is found vto be partially insoluble in aparafflnic type of lubricating oil, having a viscosity index of about 100, intended for use as a gear oil, and having a viscosity of about 90 second: Saybolt at 210 F. However, 10% by weight oi this same extreme pressure agent dissolves satisi'acttirily at ordinary temperatures without formation of hazine ss in a coastal oil (a naphthenic v base oil) having a viscosity index (V. I.) of 30 and up to about 45% chlorine although the chlorinaor coal tar solvents. For instance, paraflln .wax

afilnwax,kerosene, aromaticpetroleum fractions v n having viscosity as ht as 40 Seconds,

Saybolt at 210 'F.

may be chlorinated by passing chlorine through As another and pr fe d lfl i the the molten wax at an elevated temperature until the desired amount of chlorine has been incorporated. Temperatures up-to about-175 F. are

I invention, 100'parts by volume of the same par- 'afinie lubricating oil referred to above 'wert blended with 10 parts by volume of a phenol expractical for chlorinating the wax to a content tract having a, viscosity index 01' -1o and a v1,-

- of about 55-60 seconds Saybolt at 210 F.

percent by weight of the extreme pressure agent cosity of about 75-80 seconds Saybolt at 210 1''. obtained from a paramnic crude having a viscosity described above was then incorporated into the resultant lubricating oil blend'which had a viscosity index of about 75, and was found satisfactorily soluble therein..

These tests indicate that aromatic materials such as highly aromatic oils and aromatic solvent extracts of mineral oils are eflfected solubilizers for paraflinic lubricating oils and extreme pressure agents normally insoluble therein. In preparing extreme pressure lubricants according to this invention, other known addition agents may be incorporated if desired, for instance, fatty oils, soaps or fatty acids or naphthenic acids, other materials having thickening, viscosity index improving and pour-depressing properties, anti-oxidants, oil-soluble metal soaps, dyes, etc. J

, It is not intended that this invention be limited to any of. the particular examples which have I been given merely for the sake of illustrationbut only by the appended claims in which it is intended to claim all novelty inherent in the invent extract having a viscosity index at least as low as zero and obtained by treating a. mineral lubricating oil base stock with a solvent having a selective solvency for aromatic hydrocarbons.

2. Composition according to claim i'in which the extreme pressure agent was obtained by chlorlnating a refined kerosene at a temperature substantially above KB. to a chlorine content substantially above 25%.

3. Lubricant according to claim 1 in which the solubilizer is a phenol extract .of a mineral lubricating oil base stockJ Y JoHN'c. ZIMMER.

GEORGE M. McNUL'I'Y. 1 

